1. Field of the Invention
The present invention relates to an information reader including an imaging device for imaging a subject illuminated with light in a first wavelength region and reading information expressed by a site for absorbing light in a second wavelength region equal to or narrower than the first wavelength region contained in the subject based on imaging signals from the imaging device.
2. Description of the Related Art
Hitherto, a method of printing a mark with an infrared light absorbing ink on a printed matter such as bills, a photograph, or the like, taking a picture of is printed matter or photograph in a state that the printed matter or photograph is illuminated with infrared light by using a sensor having sensitivity in an infrared wavelength region, and reading the mark from an imaging signal obtained by this picture-taking has been known (see, for example, JP-A-6-217125).